Adjuvanted intranasal influenza vaccine to generate lung resident-memory t cells

The National Institute of Allergy and Infectious Diseases (NIAID) awarded a Project Grant of $454,278 to The University of Kentucky Research Foundation on August 15, 2025, under the Allergy and Infectious Diseases Research program (CFDA 93.855). The project, entitled "Adjuvanted Intranasal Influenza Vaccine to Generate Lung Resident-Memory T Cells," will develop and evaluate a novel influenza vaccine formulation designed to provide broadly cross-reactive and heterosubtypic immunity. The research will characterize T cell-mediated immune responses to an enantiomer-specific cationic lipid adjuvant (R-DOTAP) administered intranasally with recombinant influenza protein vaccines, with specific emphasis on inducing lung-resident memory CD8 T cells capable of providing protective cross-reactive immunity. The project is scheduled for completion by July 31, 2027, and will be performed in Lexington, Kentucky.

The research will be conducted across two primary objectives: evaluating lung-resident memory T cell induction by the intranasal R-DOTAP adjuvanted recombinant protein vaccine, and assessing vaccine efficacy against heterosubtypic influenza A challenge in preclinical models. The Cleveland Clinic Foundation has been engaged as a sub-awardee to provide scientific expertise in influenza challenge experiments, supply influenza virus stocks for challenge studies, and perform hemagglutination inhibition assays on up to 40 samples across H1N1 and H3N2 viral strains to demonstrate neutralizing titers. Upon completion, the characterization of R-DOTAP's capacity to induce lung-resident T cells is expected to advance next-generation vaccine development methodologies and contribute to the broader adjuvant development field.

Abstract

Influenza vaccine capable of providing broadly cross-reactive and heterosubtypic immunity (HSI) is a strategic solution to overcome the uncertainties associated with annual influenza immunizations. Lung resident memory CD8 t cells are important players in heterosubtypic immunity and protection after influenza infections. Current vaccine technologies used in influenza vaccines are not very effective in generating lung resident t cell memory, with the exception of live attenuated influenza vaccines (laiv). We have recently demonstrated an enantiomer specific 1,2-dioleoyl-3-trimethylammonium-propane (r-dotap) as immune stimulatory cationic lipid (CL), which can adjuvant intramuscularly administered recombinant proteins to generate robust cellular and antibody mediated response. In preliminary studies, we observed this CL can also induce potent immune responses when administered intranasally. In this proposal, we will characterize t cell-mediated immune responses to r-dotap adjuvanted influenza vaccines delivered as an intranasal formulation with emphasis on its ability to generate tissue-resident memory CD8 t cells and provide protective and cross-reactive CD8 t cell immunity to an infection challenge. In the first specific aim we will evaluate lung-resident memory t cell induction by intranasal r-doap adjuvanted recombinant protein vaccine. In the second specific aim, we will evaluate the vaccines efficacy to protect mice from a heterosubtypic influenza a challenge. A thorough characterization of r-dotap's ability to induce lung resident t cells will be useful for the adjuvant development field and contribute to the development of effective next-generation vaccines.